diff options
Diffstat (limited to 'include/block')
| -rw-r--r-- | include/block/block_int-common.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index d7c0a7e96f..95392052c9 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -120,6 +120,19 @@ struct BlockDriver { */ bool is_filter; /* + * Only make sense for filter drivers, for others must be false. + * If true, filtered child is bs->backing. Otherwise it's bs->file. + * Only two internal filters use bs->backing as filtered child and has this + * field set to true: mirror_top and commit_top. + * + * Never create any more such filters! + * + * TODO: imagine how to deprecate this behavior and make all filters work + * similarly using bs->file as filtered child. + */ + bool filtered_child_is_backing; + + /* * Set to true if the BlockDriver is a format driver. Format nodes * generally do not expect their children to be other format nodes * (except for backing files), and so format probing is disabled |